SolidWorks Assembly is drifting in space in 3DVIA 2013

I've opened a SolidWorks 2012 SP4 assembly into 3DVIA 2013 (x64) on Win7 and the model is drifting in space.  I can't get it to stop moving, and all the commands on the Ribbon are frozen.  I cannot click on anything.

Has anyone seen this behavior?  Is there a simple setting I'm missing?

Thanks,

Matt

SolidworksComposer